000
FGUS73 KBIS 191614
ESFBIS
NDC009-013-023-049-061-069-075-079-101-281800-
PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE BISMARCK ND
1014 AM CST THU FEB 19 2015
...SPRING FLOOD AND WATER RESOURCES OUTLOOK...
THIS PROBABILISTIC FLOOD OUTLOOK IS FOR THE SOURIS (MOUSE) RIVER
BASIN OF WESTERN AND CENTRAL NORTH DAKOTA...COVERING THE TIME PERIOD
OF LATE FEBRUARY THROUGH LATE MAY.
THE FOLLOWING MESSAGE HAS FOUR DISTINCT SECTIONS. THE FIRST PROVIDES
TEXT ON NOTABLE HIGHLIGHTS OF THE PROBABILITIES FOUND IN THIS
OUTLOOK. THE SECOND GIVES THE CURRENT PROBABILITIES BASED ON
EXISTING CONDITIONS (CS) AND THE NORMAL, OR HISTORICAL (HS) RISK OF
THOSE LOCATIONS REACHING THEIR RESPECTIVE MINOR, MODERATE, OR MAJOR
FLOOD CATEGORIES. THE THIRD SECTION PROVIDES THE CURRENT
PROBABILITIES OF THE RIVER REACHING THE LISTED STAGES. FINALLY, THE
FOURTH SECTION LISTS THE PROBABILITY OF THE LISTED LOCATIONS OF
FALLING TO THE SPECIFIED LEVELS.
...FLOOD OUTLOOK OVERVIEW HIGHLIGHTS...
THE RANGE OF PROBABILITIES FOR REACHING FLOOD STAGE ALONG THE SOURIS
IS GENERALLY CENTERED AROUND NORMAL WITH A FEW LOCATIONS ABOVE
NORMAL, AND SOME BELOW NORMAL. THIS TENDS TO BE CONSISTENT WITH THE
SASKATCHEWAN WATER SECURITY AGENCY SPRING RUNOFF FORECAST WHICH
DEPICTS RUNOFF AS BEING NEAR THE HISTORICAL MEDIAN.
...CURRENT CONDITIONS...
WATER EQUIVALENT IN THE SNOWPACK ACROSS THE SOURIS RIVER BASIN
RANGES FROM AROUND 1.0 INCHES OF WATER IN THE SOUTHERN PART OF THE
BASIN NEAR MINOT, TO ALMOST 2 INCHES OF WATER IN THE UPPERMOST
HEADWATERS OF SASKATCHEWAN.
...WEATHER OUTLOOK...
BELOW NORMAL TEMPERATURES AND BELOW NORMAL PRECIPITATION ARE FAVORED
IN THE 6 TO 10 AND 8 TO 14 DAY OUTLOOKS. LOOKING FORWARD TO THE ONE
MONTH AND THREE MONTH OUTLOOKS, THERE IS AN EQUAL CHANCE FOR ABOVE
NORMAL, NORMAL, AND BELOW NORMAL TEMPERATURES AND PRECIPITATION.
...SUMMARY OF HYDROLOGIC CONDITIONS...
WITHIN THE CURRENT CONDITIONS, FROST DEPTH, WATER EQUIVALENT IN THE
SNOWPACK, AND SOIL MOISTURE ARE ALL WELL WITHIN NORMAL RANGE FOR
THIS TIME OF YEAR. THE ONLY ABOVE NORMAL CONITION THAT IS USED FOR
HELPING DETERMINE FLOOD RISK IS THE LEVEL OF WATER WITHIN THE SMALL
SURFACE WATERS OF WETLANDS, PONDS, AND SLOUGHS. THESE REMAIN ABOVE
HISTORICAL NORMAL LEVELS AND WILL BE A FACTOR IN THE AMOUNT AND RATE
OF RUNOFF FROM EARLY SPRING RAINS AND MELTING SNOW. ALL RIVERS AND
STREAMS ARE WITHIN THEIR NORMAL RANGE FOR THIS TIME OF YEAR.
SIMILARLY, ALL FLOOD CONTROL DAMS HAVE REACHED THEIR SPECIFIED
DRAWDOWN LEVELS FOR THIS TIME OF YEAR. ICE COVER ON ALL RIVERS AND
STREAMS IS INTACT, BUT THERE ARE NO INDICATIONS IT IS IN EITHER AN
UNUSUAL AMOUNT, OR THAT AN ENHANCED RISK OF ICE JAMS EXISTS.
...LONG-RANGE PROBABILISTIC RIVER OUTLOOK BY FLOOD CATEGORY...
SOURIS RIVER BASIN
LONG-RANGE PROBABILISTIC OUTLOOK
VALID FROM FEBRUARY 23, 2015 TO MAY 24, 2015
THE TABLE BELOW GIVES BOTH THE CURRENT CHANCES (CS) AND THE
NORMAL/HISTORICAL CHANCES (HS) FOR EXCEEDING THE MINOR, MODERATE
AND MAJOR FLOOD STAGES AT THE RIVER FORECAST POINT LOCATIONS DURING
THE VALID PERIOD OF THIS OUTLOOK.
PROBABILITIES FOR MINOR, MODERATE, AND MAJOR FLOODING
TABLE 1 : CURRENT AND HISTORICAL
: CHANCES OF EXCEEDING FLOOD
: CATEGORY IN PERCENT (%)
CATEGORICAL :
FLOOD STAGES (FT) : MINOR MODERATE MAJOR
LOCATION MINOR MOD MAJOR : CS HS CS HS CS HS
-------- ------ ------ ------ : --- --- --- --- --- ---
DES LACS RIVER.....
FOXHOLM 16.0 18.0 19.0 : <5 <5 <5 <5 <5 <5
SOURIS RIVER.....
SHERWOOD 18.0 20.0 25.0 : <5 6 <5 <5 <5 <5
SOURIS NR FOXHOLM 10.0 13.0 15.0 : 64 55 46 41 <5 <5
MINOT 4NW 14.0 17.0 22.0 : 7 16 6 <5 <5 <5
MINOT 1549.0 1551.0 1555.0 : <5 <5 <5 <5 <5 <5
LOGAN 34.0 36.0 38.0 : 20 21 6 9 <5 <5
SAWYER 22.0 24.0 26.0 : 6 9 <5 <5 <5 <5
VELVA 1505.0 1510.0 1515.0 : 12 20 <5 <5 <5 <5
WINTERING RIVER.....
KARLSRUHE 7.0 9.0 10.0 : <5 12 <5 <5 <5 <5
SOURIS RIVER.....
TOWNER 52.0 54.0 56.0 : 70 66 43 46 6 10
BANTRY 11.0 12.0 14.0 : 61 63 46 49 <5 9
WILLOW CREEK.....
WILLOW CITY 10.0 14.0 16.0 : 36 36 6 16 <5 <5
SOURIS RIVER.....
WESTHOPE 10.0 14.0 16.0 : 46 52 7 24 7 18
LEGEND:
CS = CONDITIONAL SIMULATION (OUTLOOK FOR CURRENT CONDITIONS)
HS = HISTORICAL SIMULATION (HISTORICAL RISK FOR THIS SEASON)
FT = FEET ABOVE ZERO DATUM FOR GAGE
...LONG-RANGE PROBABILISTIC OUTLOOK BY RIVER STAGE...
SOURIS RIVER BASIN
LONG-RANGE PROBABILISTIC OUTLOOK
THE TABLE BELOW GIVES THE CURRENT 95 THROUGH 5 PERCENT CHANCES FOR
EXCEEDING RIVER STAGES AT THE RIVER FORECAST POINT LOCATIONS DURING
THE VALID PERIOD OF THIS OUTLOOK.
EXAMPLE: DURING THE VALID TIME OF THIS OUTLOOK...THERE IS A
95 PERCENT CHANCE FOR THE SOURIS RIVER AT SHERWOOD TO
RISE ABOVE 5.4 FEET AND ONLY A 5 PERCENT CHANCE THAT
IT WILL RISE ABOVE 14.0 FEET.
PROBABILITIES FOR EXCEEDING LISTED RIVER STAGES
FROM 2/23/2015 TO 5/24/2015
TABLE 2
LOCATION 95% 90% 75% 50% 25% 10% 05%
-------- ----- ----- ----- ----- ----- ----- -----
DES LACS RIVER.....
FOXHOLM 5.4 5.6 6.5 7.3 8.0 9.0 14.0
SOURIS RIVER.....
SHERWOOD 8.3 8.9 10.7 13.4 16.5 16.9 17.7
SOURIS NR FOXHOLM 7.9 8.0 9.3 12.5 14.1 14.4 14.4
MINOT 4NW 5.9 6.0 7.3 9.8 12.9 13.8 18.1
MINOT 1541.4 1541.5 1541.9 1543.2 1544.7 1545.4 1549.1
LOGAN 23.4 23.6 25.7 29.0 33.5 34.9 36.7
SAWYER 9.2 9.3 11.1 15.1 18.9 21.1 23.2
VELVA 1492.3 1492.6 1495.3 1500.0 1504.1 1505.7 1507.5
WINTERING RIVER.....
KARLSRUHE 2.9 3.0 3.1 3.3 3.7 5.0 6.7
SOURIS RIVER.....
TOWNER 48.5 48.7 51.2 53.4 54.6 55.5 56.2
BANTRY 6.5 6.8 9.1 11.6 12.6 13.3 14.0
WILLOW CREEK.....
WILLOW CITY 5.4 5.5 5.9 8.8 11.8 13.0 14.6
SOURIS RIVER.....
WESTHOPE 7.9 8.0 8.8 9.6 11.3 13.1 17.2
...LONG-RANGE PROBABILISTIC OUTLOOK BY RIVER STAGE...
SOURIS RIVER BASIN
LONG-RANGE PROBABILISTIC OUTLOOK
THE TABLE BELOW GIVES THE CURRENT 95 THROUGH 5 PERCENT CHANCES FOR
THE RIVERS TO FALL BELOW THE LISTED RIVER STAGES AT THE RIVER
FORECAST
POINT LOCATIONS DURING THE VALID PERIOD OF THIS OUTLOOK.
EXAMPLE: DURING THE VALID TIME OF THIS OUTLOOK...THERE IS A
95 PERCENT CHANCE FOR THE SOURIS RIVER AT SHERWOOD TO
REMAIN ABOVE 0.6 FEET AND ONLY A 5 PERCENT CHANCE THAT
IT WILL FALL BELOW 0.6 FEET.
PROBABILITIES FOR FALLING BELOW LISTED RIVER STAGES
2/23/2015 - 5/24/2015
TABLE 3
LOCATION 95% 90% 75% 50% 25% 10% 05%
-------- ----- ----- ----- ----- ----- ----- -----
DES LACS RIVER.....
FOXHOLM 4.7 4.7 4.7 4.6 4.6 4.6 4.6
SOURIS RIVER.....
SHERWOOD 0.6 0.6 0.6 0.6 0.6 0.6 0.6
SOURIS NR FOXHOLM 4.5 4.5 4.5 4.5 4.5 4.5 4.5
MINOT 4NW 3.9 3.9 3.9 3.9 3.9 3.9 3.9
MINOT 1536.2 1536.2 1536.2 1536.2 1536.1 1536.0 1536.0
LOGAN 18.7 18.7 18.7 18.7 18.7 18.7 18.7
SAWYER 5.5 5.5 5.5 5.5 5.5 5.4 5.4
VELVA 1489.0 1489.0 1489.0 1489.0 1489.0 1489.0 1489.0
WINTERING RIVER.....
KARLSRUHE 1.6 1.6 1.6 1.6 1.6 1.6 1.6
SOURIS RIVER.....
TOWNER 43.7 43.7 43.7 43.7 43.7 43.6 43.5
BANTRY 1.9 1.9 1.9 1.9 1.9 1.8 1.7
WILLOW CREEK.....
WILLOW CITY 4.6 4.6 4.6 4.6 4.6 4.6 4.6
SOURIS RIVER.....
WESTHOPE 6.3 6.3 6.1 6.0 5.9 5.9 5.9
...THE OUTLOOK PRODUCTION PROCESS...
THIS LONG RANGE PROBABILISTIC OUTLOOK IS BASED ON A SERIES OF PEAK
RIVER LEVELS OR CRESTS TAKEN FROM THE FORECAST HYDROGRAPH RESULTS
OF THE NWS ENSEMBLE STREAMFLOW PREDICTION MODEL (ESP). THE MODEL
IS RUN FOR MULTIPLE SCENARIOS STARTING AT CURRENT RIVER...SNOW AND
SOIL CONDITIONS AND USING NEARLY 50 YEARS OF PAST PRECIPITATION AND
TEMPERATURE CONDITIONS IN THE HISTORICAL RECORD. THESE CRESTS CAN
THEN
BE RANKED FROM LOWEST TO HIGHEST, AND THEN BE ASSIGNED AN
EXCEEDANCE PROBABILITY. FOR EXAMPLE...FOR A SERIES OF 50 YEARS...
THE LOWEST RANKED CREST HAS 49 CRESTS ABOVE IT AND SINCE 95 PERCENT
OF THE CRESTS ARE ABOVE IT, IT IS ASSIGNED A 95 PERCENT
PROBABILITY OF EXCEEDANCE (POE).
THE PROBABILITIES CAN BE USED FOR RISK MANAGEMENT BY COMPARING THIS
YEARS CURRENT TEMPERATURE AND PRECIPITATION OUTLOOKS WITH
THOSE OF PAST YEARS USED IN THE HYDRO OUTLOOK. THEY CAN ALSO BE
USED AS AN INDICATION OF THE RANGE OF CRESTS THAT MAY BE EXPECTED
DURING THE VALID PERIOD OF THE OUTLOOK.
BY PROVIDING A RANGE OF PEAK RIVER LEVEL PROBABILITIES, THE NWS IS
IS CONTRIBUTING TO THE AREAS DECISION SUPPORT SERVICES THAT HELP
WITH LONG RANGE FLOOD PLANNING AND RESPONSE READINESS. THIS OUTLOOK
IS A PART OF NOAA/S NATIONAL WEATHER SERVICE/S AHPS (ADVANCED
HYDROLOGIC PREDICTION SERVICES).
THIS OUTLOOK WAS PRODUCED USING PRECIPITATION AND TEMPERATURES
FOR THE YEARS 1948 THROUGH 2011.
...ADDITIONAL INFORMATION SOURCES...
THE AHPS LONG RANGE PROBABILISTIC HYDROLOGIC OUTLOOKS ARE ISSUED
NEAR THE END OF EACH MONTH. HOWEVER, SPRING FLOOD AND WATER
RESOURCES OUTLOOKS ARE ISSUED SEVERAL TIMES DURING THE CRITICAL
SPRING MELT PERIOD, USUALLY ON THURSDAYS BEGINNING IN LATE
FEBRUARY OR EARLY MARCH AND ENDING IN EARLY APRIL, DEPENDING
ON THE SPRING FLOODING CONDITIONS.
THIS OUTLOOK IS ALSO PRESENTED AS GRAPHS OF THE PROBABILITY OF STAGE
EXCEEDANCE FOR THE FULL PERIOD AND FOR WEEKLY INTERVALS DURING THE
PERIOD. THESE GRAPHS...TOGETHER WITH EXPLANATIONS THAT HELP IN
INTERPRETING THEM ARE AVAILABLE FROM THE NWS BISMARCK AHPS WEB
PAGE ON THE INTERNET AT:
WWW.WEATHER.GOV/BISMARCK OR WEATHER.GOV/BIS
THEN CLICK ON THE "RIVERS AND LAKES AHPS" ON THE TAB ABOVE THE
MAP...OR ON THE LINK IN THE BLUE-LEFT-HAND BANNER.
CURRENT RIVER CONDITIONS FOR ALL FORECAST POINTS WITHIN THE SOURIS
RIVER BASIN ARE AVAILABLE ON OUR WEB SITE, AS WELL AS THE FORECASTS
WHEN THE RIVER AT THE FORECAST POINT IS IN OR NEAR FLOOD.
IF YOU HAVE ANY QUESTIONS, CONTACT THE NWS AT 701-250-4495.
PROBABILISTIC HYDROLOGIC OUTLOOKS WILL BE ISSUED MONTHLY THROUGHOUT
THE REST OF THE YEAR DURING THE LATER PART OF THE MONTH OR AS
CONDITIONS WARRANT.
$$
AJS